<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<script>
function Person(){
    this.name = "李四";
    this.toString = function (){
        return "name:" + this.name
    }
}
var p = new Person();
console.log(p.toString());
</script>
</body>
</html>